Legal claims defining the scope of protection. Each claim is shown in both the original legal language and a plain English translation.
1. An asynchronous system for localization of nodes in a wireless network architecture, comprising: first and second wireless nodes each having known locations and including a wireless device with one or more processing units and RF circuitry for transmitting and receiving communications in the wireless network architecture; and a wireless sensor node having an unknown location and including a wireless device with RF circuitry to enable communications with the first and the second wireless nodes in the wireless network architecture, wherein the one or more processing units of the first wireless node are configured to execute instructions to transmit a first communication to the second wireless node and the wireless sensor node, to receive a second communication with an acknowledgement packet from the wireless sensor node, and to determine time difference of arrival information of the reception of the second communication between each of the first and the second wireless nodes, wherein a transmission time of the first communication being transmitted from the first wireless node to the wireless sensor node is used as a time reference for each of the first and the second wireless nodes.
This invention relates to a wireless network system for localizing nodes with unknown positions using time difference of arrival (TDOA) techniques. The system addresses the challenge of accurately determining the location of wireless sensor nodes in a network where some nodes have known positions. The architecture includes at least two reference nodes with known locations, each equipped with processing units and RF circuitry for wireless communication. A sensor node with an unknown location communicates with these reference nodes. The first reference node transmits a signal to both the second reference node and the sensor node. The sensor node responds with an acknowledgement packet, which is received by both reference nodes. The system calculates the time difference of arrival (TDOA) of the acknowledgement packet at each reference node, using the transmission time of the initial signal as a common time reference. This TDOA data is then used to triangulate the sensor node's position. The approach leverages asynchronous communication, eliminating the need for synchronized clocks between nodes, which simplifies deployment and reduces infrastructure requirements. The system is particularly useful in applications requiring real-time localization, such as asset tracking, environmental monitoring, and industrial automation.
2. The asynchronous system of claim 1 , further comprising: a third wireless node including a wireless device with one or more processing units and RF circuitry for transmitting and receiving communications in the wireless network architecture wherein the one or more processing units of the first wireless node are configured to execute instructions for a multilateration algorithm to determine a location of the wireless sensor node using the time difference of arrival information between the first and the second wireless nodes and also between the first and the third wireless nodes.
This invention relates to an asynchronous wireless network system for determining the location of a wireless sensor node using multilateration. The system addresses the challenge of accurately locating wireless devices in environments where precise timing synchronization is difficult or impractical. The system includes at least three wireless nodes, each equipped with a wireless device containing processing units and RF circuitry for transmitting and receiving communications. The first wireless node executes a multilateration algorithm to calculate the location of the wireless sensor node by analyzing time difference of arrival (TDOA) information. The algorithm uses TDOA data from signals received by the first node in relation to the second and third wireless nodes. The third wireless node, like the others, includes processing units and RF circuitry to participate in the communication and location determination process. By leveraging multiple nodes, the system improves location accuracy without requiring strict synchronization, making it suitable for dynamic or resource-constrained wireless networks. The multilateration algorithm processes the TDOA data to triangulate the sensor node's position, enhancing reliability in asynchronous environments.
3. The asynchronous system of claim 1 , wherein the first wireless node has a first reference clock signal and the second wireless node has a second reference clock signal.
This invention relates to asynchronous wireless communication systems, specifically addressing synchronization challenges between wireless nodes operating with independent reference clock signals. The system includes at least two wireless nodes that communicate asynchronously, meaning they lack a shared time reference or synchronization mechanism. Each node operates using its own reference clock signal, which may drift or differ in frequency from the other node's clock. The system enables reliable communication despite these clock discrepancies, ensuring data integrity and timing accuracy without requiring a centralized or synchronized clock infrastructure. The invention may involve techniques for compensating for clock drift, aligning timing windows, or managing data transmission and reception based on local clock references. The solution is particularly useful in distributed wireless networks where nodes operate independently, such as in IoT, sensor networks, or ad-hoc communication systems. By allowing nodes to function asynchronously while maintaining communication reliability, the system reduces complexity and cost compared to synchronized systems. The invention may also include methods for estimating clock offsets, adjusting transmission timing, or handling data buffering to accommodate clock differences. The overall goal is to enable robust wireless communication in environments where clock synchronization is impractical or undesirable.
4. The asynchronous system of claim 2 , wherein one or more processing units of the wireless sensor node are configured to execute instructions to transmit the second communication including the acknowledgement packet to the first, the second, and the third wireless nodes in response to receiving the first communication with a forward packet from the first node.
This invention relates to wireless sensor networks and addresses the challenge of efficient and reliable communication in asynchronous systems where nodes operate independently without strict synchronization. The system involves a wireless sensor node that receives a first communication containing a forward packet from a first wireless node. In response, the node transmits a second communication that includes an acknowledgement packet to the first node, as well as to a second and a third wireless node. This ensures that multiple nodes in the network are aware of the transmission, improving reliability and coordination in an asynchronous environment. The processing units within the wireless sensor node execute instructions to handle these communications, facilitating seamless data exchange and acknowledgment across the network. The system enhances robustness by ensuring that critical information is propagated to multiple nodes, reducing the risk of data loss or miscommunication in decentralized wireless sensor networks. The approach is particularly useful in applications where nodes may have varying power states or intermittent connectivity, as it allows for flexible and adaptive communication strategies.
5. The asynchronous system of claim 4 , wherein one or more processing units of the second and the third wireless nodes are configured to execute instructions to receive communications including forward packets from the first wireless node and acknowledgement packets from the wireless sensor node, to record a timestamp and channel sense information for each of the received forward and acknowledgement packets.
This invention relates to wireless communication systems, specifically asynchronous networks where nodes operate without strict synchronization. The problem addressed is the need for efficient and reliable data forwarding in such networks, particularly in scenarios involving wireless sensor nodes that may have limited power or processing capabilities. The system includes multiple wireless nodes, including a first wireless node that forwards data packets and a wireless sensor node that sends acknowledgment packets. The second and third wireless nodes in the system are equipped with processing units that execute instructions to receive both forward packets from the first wireless node and acknowledgment packets from the wireless sensor node. These processing units record a timestamp and channel sense information for each received packet. The timestamp captures the exact time of reception, while the channel sense information provides details about the communication channel's state at the time of reception. This recorded data can be used to optimize routing, reduce collisions, and improve overall network efficiency by analyzing packet transmission patterns and channel conditions. The system ensures reliable data transmission in asynchronous environments by leveraging timestamp and channel sensing data to enhance decision-making processes.
6. The asynchronous system of claim 5 , wherein a transmission time of the forward packet from the first wireless node is used as a time reference for the first, the second, and the third wireless nodes.
This invention relates to asynchronous wireless communication systems, specifically addressing synchronization challenges in multi-node networks where precise timing references are needed for coordinated operations. The system involves at least three wireless nodes operating without a centralized clock, where one node transmits a forward packet that serves as a time reference for all nodes. The transmission time of this forward packet from the first node is used to synchronize the first, second, and third nodes, enabling coordinated actions such as data transmission, reception, or other time-sensitive operations. The system may include mechanisms to compensate for propagation delays or processing times to ensure accurate synchronization across nodes. This approach eliminates the need for dedicated synchronization signals or infrastructure, reducing complexity and power consumption in decentralized wireless networks. The invention is particularly useful in applications like sensor networks, mesh networks, or ad-hoc communications where nodes must operate asynchronously but require temporal alignment for reliable data exchange.
7. The asynchronous system of claim 6 , wherein the time difference of arrival information between the first and the second wireless nodes is determined based on a first time when the first wireless node receives the acknowledgement packet from the wireless sensor node, a second time when the second wireless node receives the acknowledgement packet from the wireless sensor node, and the time reference.
The invention relates to wireless communication systems, specifically asynchronous systems where precise timing synchronization is challenging. The problem addressed is accurately determining the time difference of arrival (TDOA) of signals between wireless nodes in an asynchronous network, where nodes lack synchronized clocks. TDOA is critical for applications like localization, positioning, and network synchronization but is difficult to achieve without precise time references. The system includes a wireless sensor node that transmits a packet to a first wireless node and a second wireless node. Each wireless node sends an acknowledgement packet back to the sensor node. The sensor node then transmits an acknowledgement packet to both wireless nodes, which includes a time reference derived from the sensor node's clock. The first and second wireless nodes use this time reference to determine the time difference of arrival (TDOA) of the acknowledgement packet. The TDOA is calculated based on the first time when the first wireless node receives the acknowledgement packet, the second time when the second wireless node receives the acknowledgement packet, and the time reference provided by the sensor node. This method enables accurate TDOA estimation in an asynchronous system without requiring synchronized clocks between the wireless nodes. The approach improves localization and synchronization in wireless networks where precise timing is essential.
8. The asynchronous system of claim 7 , wherein the one or more processing units of the first wireless node are configured to execute instructions to determine a difference between the first time and the time reference and also determine a difference between the second time and the time reference.
This invention relates to asynchronous wireless communication systems, specifically addressing synchronization challenges in distributed networks where nodes operate without a shared clock. The problem solved is the lack of precise timing alignment between wireless nodes, which can lead to communication errors, inefficient resource usage, and degraded performance in time-sensitive applications. The system includes a first wireless node with one or more processing units and a second wireless node. The first wireless node receives a first time from the second wireless node and a second time from a third wireless node. The processing units then calculate the difference between the first time and a local time reference, as well as the difference between the second time and the same time reference. This enables the first wireless node to assess timing discrepancies between itself and other nodes, facilitating synchronization or coordination in an asynchronous network. The system may also include additional nodes and processing units to further refine timing adjustments or support distributed synchronization protocols. The invention improves network reliability and efficiency by dynamically compensating for timing offsets in decentralized wireless environments.
9. The asynchronous system of claim 7 , wherein the one or more processing units of the first wireless node are configured to execute instructions to determine the time difference of arrival information based on determining time of flight estimates for localization that are based on time estimates of round trip time of communications between the first and the second wireless nodes and communications between the first and the third wireless nodes.
This invention relates to wireless communication systems, specifically asynchronous systems for determining the location of wireless nodes. The problem addressed is the challenge of accurately localizing wireless nodes in environments where precise time synchronization between nodes is not available, which is common in many wireless networks. The solution involves using time difference of arrival (TDOA) techniques to estimate the position of a wireless node without requiring synchronized clocks. The system includes at least three wireless nodes, where one node (the first node) communicates with two other nodes (the second and third nodes). The first node calculates the time difference of arrival of signals from the second and third nodes by estimating the time of flight (TOF) of round-trip communications between the nodes. These TOF estimates are derived from the round-trip time (RTT) measurements of signals exchanged between the first node and the second node, and between the first node and the third node. By analyzing these RTT-based TOF estimates, the system determines the TDOA information, which can then be used to compute the position of the first node relative to the other nodes. This approach eliminates the need for synchronized clocks, making it suitable for asynchronous wireless networks where precise timing is difficult to maintain. The method leverages existing communication signals, reducing the need for additional infrastructure or specialized hardware.
10. An apparatus, comprising: a memory for storing instructions; one or more processing units to execute instructions for controlling a plurality of wireless sensor nodes in a wireless network architecture and asynchronously determining locations of the plurality of wireless sensor nodes; and radio frequency (RF) circuitry to transmit communications to and receive communications from the plurality of wireless sensor nodes each including a wireless device with RF circuitry to enable bi-directional communications with the RF circuitry of the apparatus in the wireless network architecture, wherein the one or more processing units of the apparatus are configured to execute instructions to transmit a first communication to a first and a second wireless sensor node each having a known location, and a third wireless sensor nodes having an unknown location, to receive a second communication with an acknowledgement packet from the third wireless sensor node, to determine time difference of arrival information between the apparatus and the first wireless sensor node based on when each of the apparatus and the first wireless nodes receive the acknowledgement packet from the third wireless sensor node, and to determine time difference of arrival information of the reception of the second communication between each of the apparatus and the second wireless sensor node, wherein a transmission time of the first communication being transmitted from the apparatus is used as a time reference for each of the apparatus and the first wireless node.
A wireless network system includes an apparatus that controls multiple wireless sensor nodes and asynchronously determines their locations. The apparatus has a memory, processing units, and RF circuitry for bidirectional communication with the sensor nodes. Each sensor node includes a wireless device with RF circuitry to communicate with the apparatus. The system operates by transmitting a first communication to a first and second sensor node with known locations and a third sensor node with an unknown location. The third sensor node responds with an acknowledgement packet, which the apparatus and the first sensor node receive. The apparatus calculates time difference of arrival (TDOA) information between itself and the first sensor node based on when each receives the acknowledgement packet. Similarly, the apparatus determines TDOA information for the second communication received from the second sensor node. The transmission time of the first communication serves as a time reference for these calculations. This method enables precise location determination of the third sensor node by leveraging known positions of the first and second nodes and timing data from the acknowledgement packet. The system is designed for efficient, asynchronous localization in wireless networks, addressing challenges in tracking mobile or dynamically placed sensor nodes without requiring synchronized timekeeping across all devices.
11. The apparatus of claim 10 , wherein the one or more processing units of the apparatus are configured to execute instructions for a multilateration algorithm to determine a location of the third wireless sensor node using the time difference of arrival information.
This invention relates to wireless sensor networks and the precise localization of sensor nodes within such networks. The problem addressed is the challenge of accurately determining the position of a wireless sensor node in a network where multiple nodes communicate wirelessly, but the exact location of at least one node is initially unknown. Traditional methods often rely on signal strength or angle-based techniques, which can be unreliable due to environmental interference or multipath effects. The apparatus includes multiple wireless sensor nodes, each capable of transmitting and receiving wireless signals. At least one of these nodes has a known location, serving as a reference point. The apparatus also includes one or more processing units configured to analyze time difference of arrival (TDOA) information from signals exchanged between the nodes. By processing these time differences, the multilateration algorithm calculates the position of an unknown node relative to the reference nodes. This method improves localization accuracy by leveraging precise timing measurements, reducing errors caused by signal attenuation or reflection. The system may also incorporate additional features, such as signal synchronization mechanisms to ensure accurate time measurements and error correction techniques to refine location estimates. The apparatus is particularly useful in applications requiring high-precision positioning, such as industrial automation, asset tracking, or environmental monitoring, where reliable node localization is critical for system functionality.
12. The apparatus of claim 10 , wherein the apparatus has a first reference clock signal and the first wireless sensor node has a second reference clock signal.
A system for synchronizing clock signals between a central apparatus and a wireless sensor node addresses timing discrepancies in distributed sensor networks. The apparatus generates a first reference clock signal, while the wireless sensor node operates with a second reference clock signal. The system compensates for clock drift between the two signals to ensure accurate time synchronization. The apparatus includes a receiver to capture a synchronization signal from the wireless sensor node, a processor to analyze the signal and calculate timing adjustments, and a transmitter to send correction data back to the node. The wireless sensor node adjusts its second reference clock signal based on the received correction data, aligning it with the apparatus's first reference clock signal. This synchronization is critical for applications requiring precise timing, such as industrial automation, environmental monitoring, and wireless sensor networks where coordinated data collection is essential. The system may also include additional sensor nodes, each with their own reference clock signals, all synchronized to the apparatus's primary clock. The synchronization process accounts for transmission delays and environmental factors affecting signal propagation to maintain accuracy. The apparatus may further include a memory to store synchronization parameters and a power management module to optimize energy efficiency during synchronization operations.
13. The apparatus of claim 10 , wherein the transmitted first communication includes a transmission time of a forward packet that is transmitted to the first, second, and third wireless sensor nodes with the transmission time being used as a time reference for the apparatus, the first wireless sensor node, and the second wireless sensor node.
A wireless sensor network apparatus synchronizes multiple sensor nodes using a time reference derived from a transmitted communication. The apparatus includes a central node that sends a forward packet to at least three wireless sensor nodes, with the transmission time of this packet serving as a shared time reference for the apparatus and the sensor nodes. The forward packet is used to establish a common timing framework, enabling precise synchronization across the network. The apparatus may also include additional components for processing received signals, such as a receiver and a processor, to facilitate time synchronization and data exchange. The synchronization mechanism ensures that the sensor nodes and the apparatus operate with aligned timing, improving coordination and data accuracy in applications like environmental monitoring, industrial automation, or asset tracking. The transmitted time reference allows the sensor nodes to adjust their internal clocks based on the received packet, maintaining synchronization even in dynamic or distributed environments. This approach reduces timing errors and enhances reliability in wireless sensor network operations.
14. The apparatus of claim 13 , wherein the time difference of arrival information between the apparatus and the first wireless sensor node is determined based on a first time when the apparatus receives an acknowledgement packet from the third wireless sensor node, a second time when the first wireless sensor node receives an acknowledgement packet from the third wireless sensor node, and the time reference.
This invention relates to wireless sensor networks and methods for determining the time difference of arrival (TDOA) between a wireless apparatus and a sensor node. The problem addressed is accurately calculating TDOA in distributed wireless networks where precise synchronization between devices is challenging. The apparatus includes a wireless transceiver, a processor, and a memory storing instructions for time synchronization and TDOA calculation. The apparatus communicates with a first wireless sensor node and a third wireless sensor node, which acts as a relay or reference point. The TDOA is determined by analyzing the timing of acknowledgement packets exchanged between the apparatus and the sensor nodes. Specifically, the apparatus measures a first time when it receives an acknowledgement packet from the third sensor node and a second time when the first sensor node receives the same acknowledgement packet. These timestamps, along with a shared time reference, are used to compute the TDOA. This method improves localization accuracy in wireless networks by leveraging relayed signals and synchronized timing information. The apparatus may also include additional features such as signal processing modules to enhance timing precision and reduce errors caused by environmental factors or signal propagation delays. The invention is particularly useful in applications requiring precise positioning, such as asset tracking, environmental monitoring, and industrial automation.
15. The apparatus of claim 14 , wherein the one or more processing units of the apparatus are configured to execute instructions to determine a difference between the first time and the time reference and also to determine a difference between the second time and the time reference.
This invention relates to a system for time synchronization in distributed computing environments, addressing the challenge of accurately aligning timestamps across multiple devices to ensure consistent data processing and coordination. The apparatus includes one or more processing units that execute instructions to compare timestamps from different sources against a reference time. Specifically, the system calculates the difference between a first timestamp and a reference time, as well as the difference between a second timestamp and the same reference time. This allows the apparatus to assess temporal discrepancies between the timestamps and the reference, enabling precise synchronization or error detection. The processing units may also perform additional functions, such as adjusting the timestamps based on the calculated differences or generating alerts if the discrepancies exceed predefined thresholds. The apparatus is designed to operate in environments where multiple devices generate timestamps independently, ensuring that all devices adhere to a common time standard. This synchronization is critical for applications requiring high temporal accuracy, such as financial transactions, network security, or distributed data processing. The system improves reliability by minimizing time-related errors and ensuring consistent operations across distributed systems.
16. An asynchronous system for localization of nodes in a wireless network architecture, comprising: a first, a second, and a third wireless nodes each having known locations and including a wireless device with one or more processing units and RF circuitry for transmitting and receiving communications in the wireless network architecture; and a fourth wireless node having an unknown location and including a wireless device with RF circuitry to enable communications with the first, the second, and the third wireless nodes in the wireless network architecture, wherein the one or more processing units of the first wireless node are configured to execute instructions to receive a first communication with a forward packet from the fourth wireless node, to transmit a second communication to the second, the third, and the fourth wireless nodes in response to the forward packet, and to determine time difference of arrival information of the reception of the first communication between each of the first and the second wireless nodes, wherein a transmission time of the second communication being transmitted from the first wireless node is used as a time reference for each of the first and second wireless nodes.
This invention relates to a wireless network system for localizing nodes with unknown positions using asynchronous time difference of arrival (TDOA) measurements. The system includes three reference nodes with known locations and a fourth node with an unknown location. Each node has a wireless device with processing units and RF circuitry for communication. The first reference node receives a signal from the unknown node, then broadcasts a response to the other reference nodes and the unknown node. The system measures the time difference between signal arrivals at the first and second reference nodes, using the transmission time of the response as a common time reference. This allows the unknown node's position to be estimated based on the TDOA data from multiple reference nodes. The asynchronous design avoids the need for synchronized clocks, simplifying implementation while maintaining localization accuracy. The method leverages existing wireless communications infrastructure to enable real-time positioning without dedicated hardware. This approach is useful in applications like asset tracking, indoor navigation, and IoT networks where precise node localization is required without synchronized timing systems.
17. The system of claim 16 , wherein the one or more processing units of the first wireless node are configured to execute instructions for a multilateration algorithm to determine a location of the fourth wireless node using the time difference of arrival information.
This invention relates to wireless communication systems, specifically a method for determining the location of a wireless node using multilateration techniques. The system involves multiple wireless nodes, including a first wireless node that receives time difference of arrival (TDOA) information from other nodes. The first wireless node processes this TDOA data using a multilateration algorithm to calculate the precise location of a fourth wireless node. The multilateration algorithm leverages the time differences in signal arrivals from multiple reference points to triangulate the position of the target node. This approach improves location accuracy by reducing errors caused by signal propagation delays and environmental interference. The system is particularly useful in applications requiring precise positioning, such as asset tracking, navigation, and wireless sensor networks. The use of TDOA and multilateration enhances reliability and reduces the need for complex synchronization mechanisms, making the solution scalable and efficient for real-time location tracking.
18. The system of claim 16 , wherein the first wireless node has a first reference clock signal and the second wireless node has a second reference clock signal.
A system for wireless communication includes a first wireless node and a second wireless node, where the first wireless node has a first reference clock signal and the second wireless node has a second reference clock signal. The system synchronizes the first and second reference clock signals to ensure accurate timing between the nodes. The first wireless node may transmit a synchronization signal to the second wireless node, which adjusts its clock based on the received signal to align with the first reference clock signal. This synchronization is critical for applications requiring precise timing, such as coordinated data transmission, network synchronization, or distributed sensor networks. The system may also include mechanisms to compensate for propagation delays, clock drift, or other timing errors to maintain synchronization over time. The synchronization process may involve periodic updates or continuous adjustments to ensure minimal timing discrepancies between the nodes. This technology is particularly useful in wireless networks where precise timing is essential for efficient operation, such as in industrial automation, telecommunications, or IoT (Internet of Things) applications. The system may further include error detection and correction mechanisms to handle disruptions or interference that could affect synchronization accuracy.
19. The system of claim 17 , wherein one or more processing units of the fourth wireless node are configured to execute instructions to transmit the first communication including the forward packet to the first, the second, and the third wireless nodes.
This invention relates to wireless communication systems, specifically a method for managing packet transmission in a multi-node network. The problem addressed is efficient and reliable packet forwarding in a network with multiple wireless nodes, ensuring that data is transmitted to all relevant nodes without redundancy or delay. The system includes a fourth wireless node that receives a forward packet from a source node. The fourth wireless node processes this packet and generates a first communication that includes the forward packet. This communication is then transmitted to a first, second, and third wireless nodes in the network. The fourth wireless node is equipped with one or more processing units that execute instructions to perform this transmission. The system ensures that the forward packet is distributed to all designated nodes, improving data dissemination in the network. The invention may also include additional features such as error handling, packet prioritization, or dynamic routing adjustments to optimize performance. The overall goal is to enhance communication efficiency and reliability in multi-node wireless environments.
20. The system of claim 19 , wherein one or more processing units of the second and the third wireless nodes are configured to execute instructions to receive communications including forward packets from the fourth wireless node and acknowledgement packets from the first wireless node and to record a timestamp and channel sense information for each of the received forward and acknowledgement packets.
This invention relates to wireless communication systems, specifically addressing challenges in packet transmission and acknowledgment in multi-node networks. The system involves multiple wireless nodes operating in a network where data packets are forwarded between nodes, and acknowledgment packets are sent to confirm successful transmission. A key problem addressed is the need for accurate timing and channel state information to optimize communication efficiency and reliability. The system includes at least four wireless nodes, where a first node initiates data transmission, a second node receives and forwards packets, a third node assists in relaying, and a fourth node acts as an intermediary. The second and third nodes are equipped with processing units that execute instructions to receive both forward packets from the fourth node and acknowledgment packets from the first node. For each received packet, these nodes record a timestamp and channel sense information, which includes details about the wireless channel conditions at the time of reception. This recorded data helps in analyzing transmission performance, identifying bottlenecks, and improving routing decisions. The recorded timestamps and channel sense information enable the system to track packet delivery times, assess link quality, and adapt transmission parameters dynamically. This enhances overall network reliability and throughput by ensuring that packet forwarding and acknowledgment processes are optimized based on real-time channel conditions. The system is particularly useful in scenarios where wireless communication links are prone to interference or varying signal strengths, such as in mesh networks or ad-hoc wireless systems.
21. The system of claim 20 , wherein the time difference of arrival information between the first and the second wireless nodes is determined based on a first time when the first wireless node receives a forward packet from the fourth wireless node, a second time when the second wireless node receives a forward packet from the fourth wireless node, and a time offset between the first and second reference clock signals.
Wireless communication systems often require precise synchronization and location determination between nodes. A key challenge is accurately measuring the time difference of arrival (TDOA) between signals received by different wireless nodes, which is essential for applications like positioning, synchronization, and network coordination. Existing methods may suffer from inaccuracies due to clock drift, propagation delays, or synchronization errors. This invention describes a system for determining the TDOA between a first and a second wireless node by leveraging a fourth wireless node as a reference. The system measures a first time when the first wireless node receives a forward packet from the fourth node and a second time when the second wireless node receives the same or a related forward packet from the fourth node. Additionally, the system accounts for a time offset between the reference clock signals of the first and second nodes. By combining these measurements, the system calculates the TDOA with improved accuracy, compensating for clock discrepancies and propagation effects. This approach enhances synchronization and positioning capabilities in wireless networks, particularly in scenarios where precise timing is critical, such as in distributed antenna systems, IoT networks, or wireless sensor networks. The system may also include mechanisms for adjusting transmission power, managing interference, or optimizing packet routing to further improve performance.
22. The system of claim 21 , wherein the one or more processing units of the first wireless node are configured to execute instructions to determine the time offset between the first and the second reference clock signals based on a third time when the second wireless node receives an acknowledgement packet from the first wireless node, a fourth time when the first wireless node transmits an acknowledgement packet to the second wireless node, and time of flight estimates for communications between the first and the second wireless nodes.
This invention relates to wireless communication systems, specifically to methods for synchronizing clocks between wireless nodes. The problem addressed is the need for precise time synchronization in wireless networks, where clock drift and communication delays can lead to inaccuracies in time-based operations such as positioning, scheduling, and coordination. The system includes a first wireless node and a second wireless node, each equipped with processing units and reference clock signals. The first wireless node transmits a packet to the second wireless node, which then sends an acknowledgement packet back. The first wireless node records the time it transmits the acknowledgement packet (fourth time) and the second wireless node records the time it receives the acknowledgement (third time). The system calculates the time offset between the two nodes' reference clocks using these recorded times and time-of-flight estimates for the communications between the nodes. The time-of-flight estimates account for the propagation delay of signals between the nodes, allowing for accurate compensation of transmission delays. This method enables precise synchronization of the nodes' clocks, improving the reliability and accuracy of time-sensitive operations in wireless networks.
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February 18, 2020
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